Parallel ruler



March 9, 1948. LACHMUND 2,437,469

PARALLEL RULER 1 Filed Dec. 4, 1944 o E 1 l /2 l2 nnmtmwar.

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INVENTOR JULIUS LACHMUND MM 165W ATTORNEY Patented an. 9, 1948 timePARALLEL RULiin Julius Lachmu id, San Francisco, l jj p H ApplicationDecember 4, 1944, Serial N tasha 7 s cleims. (c1. sa -1 I a structureadapted to facilitate the assembly oi" the device and its operation forobtaining uniform spacing of section lines. v Another object is toprovide a structure of a thickness not materially greater at any point"than the thickness of the triangie; and which may be readily adjusted toobtain a desired spacing of section lines drawn at any angle.

My invention possesses other objects and features of value, some ofwhich with the foregoing will be set forth in the following descriptionof the invention. It is to be understood that I do not limitmy-self tothe showing made by the said description and the drawings as I may adoptvariant forms of the invention within the scope of the appended claims.

Referring to the drawings:

Figure 1 is a fragmental View, drawn upon an enlarged scale,illustrating the structure and mounting of the slide, parts being shownin section, and

Figure 2 is a plan view of the drafting instrument.

In terms of broad inclusion, the drafting instrument of my inventioncomprises a triangle provided with a, slide mounted for limitedreciproeating movement within a guide slot adjacent one of its edges,and operable for regulating movement of the triangle to obtain uniformspacing of lines drawn along its edge. The invention contemplates astructure in which the thickness of the slide is substantially the sameas that of the triangle; and in which end pieces, assembled upon thetriangle through a widened portion of a guide slot, are adjusted bymeans of a turnbuckle to vary the length of the slide and the range ofmovement thereof relative to the triangle.

In terms of greater detail, the drafting instrument of my inventioncomprises a triangle, designated in general by the numeral I, which maybe of any suitable size and material. The 45 form of triangle shown inthe drawing is illustrative only, as a 30-60, or other form is equallyuseful.

vA guide slot .zi's-formedin thebodybf the trim angle parallel tov oneof the; edges ofthetriangle. and'spaced slightly inwardly therefrom. .jTongues 3 along the longitudinaledges or. the'slojt provide. guide railsfor engaging corresponding groove-s {4 in the edges of'a. slide mountedfor reciprocating movementwithin the slotjL ,ij. I Q

The slide comprises .3 pair, of substantially rec tangular end .pieces,.1 'slidablymova'ble along, the. guide rails 3 of the slot 2..flhepieces 'IJare made otmaterial of substantiallyfthe same thicknessas the bodyof the, triangle l; and. are. assembled into theslot 2through a wldened section8 formed substantially midway betweenthefendseither slot. The widenedsection s is one length slightly; greater thanthe length of the end piecesljjI h'e en tltq the s ot 2 sxs fficient tope m fiiat oneof'the e nd pieces lto be moved clear, of thewidenedportion 8 of the slotsojasto admitithe len i ca- The end pieces Iare adjustablyjconnefitedto. each other by means of a turnbuckle;comprising a sleeve H engaging oppositely"threadedistemsi l2 secured to.the endpieces .lrinfi'nwafrdly eX-' in x a a inemen -q .T 'e, stem-STmay :be. screw'edinto the gendpiece's after" they area'ssemfbled'ontothe triangla'orthe partsmaybe assem; bled and secured in placein any'convenientman'; ner. The 'sleevei'l is of adiameter substantiallyequal to the thickness of the triangle. Preferably the surface of thesleeve is knurled or otherwise roughened to facilitate turning thesleeve to adjust the spacing of the end pieces. Also, such knurlingprovides a roughened area which aids in holding the slide against adrawing when in use.

The end pieces 7 may be spread apart to seat against the ends of theslot 2 in an inoperative position. When in this position, the slide inno way affects or interferes with the normal operation of the trianglein its ordinary usage.

When it is desired to use the triangle for section lining, theturnbuckle is operated to draw the end pieces 1 toward each other untila desired range of movement of the slide along the slot 2 is permitted.A scale l4 may be provided at one end of the slot 2 for indicating thedistance through which the slide may be moved, the scale being readablewith respect to one end of the slide as a pointer'when the other end ofthe slide is seated against the adjacent end of the slot 2.

After the end pieces of the slide have been adjusted to give the desireddegree of movement, the triangle is placed against a straight edge (notshown) with the slide parallel thereto. The

slide is moved to the extreme right hand limit of its movement and thetriangle is placed at the starting position for the section lining. Aninitial section line is drawn, and while the slide is held firmly inplace against the drawing, the triangle is shifted along the slide tothe next position as indicated in dotted lines in Figure 2. The knurlingof the sleeve ll aids in preventing shifting of the slide as thetriangle is so moved. The triangle is then held against the drawingwhile the slide is moved to the opposite end of the slot, for definingthe next limit of movement of the triangle. and the triangle whileholding the other against th drawing, the triangle may be moved inuniform steps along the edge of the straight edge.

By alternately moving the slide Section lines drawn along the edge ofthe triangle at successive steps will be correspondingly uniformlyspaced.

Since the slide, including the turnbuckle, is of no greater thicknessthan the triangle, the device may be operated with either side of thetriangle up, and with the movement of the triangle progressing eithertoward the right or the left. The angle at which the section lines aredrawn may of course be varied by suitable positioning of the straightedge along which the triangle is operated. Lines such as the line IEdefining an angle of 30 to the hypotenuse of the triangle, may be atvarious angles, for obtaining a desired angularity of lines drawn alongthe hypotenuse. By alining the line IS with a selected base line, andmoving the straight edge against the triangle when so positioned, adesired angularity of the hypotenuse may be maintained as the triangleis moved along the straight edge.

I claim:

1. A drafting instrument comprising a triangle, a slide mounted forreciprocating movement parallel to an edge of triangle, and meanssubstantially contained within the thickness of the triangle foradjusting the length of the slide to vary the distance the slide may bemoved relative to the triangle.

2. A drafting instrument comprising a triangle, a slide mounted forreciprocating movement parallel to an edge of triangle, and a turnbucklesubstantially contained within the thickness of the triangle foradjusting the length of the slide to vary the distance the slide may bemoved relative to the triangle.

3. A drafting instrument comprising a triangle having a guide slotparallel to one of its edges. a slide mounted Within the slot forreciprocating movement therein, the thickness of the slide beingsubstantially the same as the thickness of the triangle and the triangleand slide being relatively movable while resting fiat against asupporting surface upon either of its faces, and means substantiallycontained within the thickness of the triangle for regulating the rangeof movement of the slide relative to the triangle.

4. A drafting instrument comprising a triangle having a guide slotinwardly spaced from one of its edges and having a widened sectionintermediate its ends, a slide mounted for reciprocating movement withinthe slot and comprising a pair of end pieces movable into slidingengagement with end portions of the slot through the widened centerportion, and adjustable means substantially contained within thethickness of the triangle and connecting the end pieces in a desiredspaced relation.

5. A drafting instrument comprising a triangle having a guide slotinwardly spaced from one of its edges and having a widened sectionintermediate its ends, a slide mounted for reciprocating movement withinthe slot and comprising a pair of end pieces separately movable intosliding engagement with end portions of the slot through the widenedcenter portion, and a turnbuckle connecting the end pieces in a desiredspaced relation within the slot, the thickness of the slide beingsubstantially the same as that of the triangle whereby the triangle andslide may lie with either face flat against a supporting surface.

JULIUS LACHMUND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNl TED STATES PATENTS Number Name Date 822,160 Shilling May 29, 1906951,719 Baum Mar. 8, 1910 2,183,214 LeLisle Dec. 12, 1939

